Skip to main content

ActiveMQ Java Maven Hello world

Create a Maven quick start project from STS.

Pom.xml

Now open pom.xml and add the required dependencies.

<dependency>
            <groupId>org.apache.activemq</groupId>
            <artifactId>activemq-all</artifactId>
            <version>5.0.0</version>
            <exclusions>
                <exclusion>
                    <groupId>org.apache.activemq</groupId>
                    <artifactId>activeio-core</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.apache.xbean</groupId>
            <artifactId>xbean-spring</artifactId>
            <version>3.7</version>
      </dependency>

add dependency activemq-all version 5. while building if you get a error saying activeio-core is missing add a exclusion. If its required xbean dependency add as above.

Sender.java 

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;


public class Sender {

    private ConnectionFactory factory = null;
    private Connection connection = null;
    private Session session = null;
    private Destination destination = null;
    private MessageProducer producer = null;
   
    public void sendMessage(){
       
        try{
            factory = new ActiveMQConnectionFactory(ActiveMQConnection.DEFAULT_BROKER_URL);
            connection = factory.createConnection();
            connection.start();
           
            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            destination = session.createQueue("SAMPLEQUEUE");
            producer = session.createProducer(destination);
            TextMessage message = session.createTextMessage();
            message.setText("Hello ...This is a sample message..sending from FirstClient");
            producer.send(message);
            System.out.println("Sent: "+message.getText());
           
        } catch (JMSException e){
            e.printStackTrace();
        }       
    }   
}
 

Create send class as above.

App.java


public class App
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
       
        Sender sender = new Sender();
        sender.sendMessage();
    }
}

Add above code to the main method. 

Executing  

Now start your local ActiveMq up and running.
execute your application.
go to admin view of activemq browser
you will see a new message there.
Our queue name is SAMPLEQUEUE


Receiver.java

lets create the consumer now.

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;

public class Receiver {

    private ConnectionFactory factory = null;
    private Connection connection = null;
    private Session session = null;
    private Destination destination = null;
    private MessageConsumer consumer = null;

    public void receiveMessage() {

        factory = new ActiveMQConnectionFactory(
                ActiveMQConnection.DEFAULT_BROKER_URL);
        try {
            connection = factory.createConnection();

            connection.start();

            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            destination = session.createQueue("SAMPLEQUEUE");
            consumer = session.createConsumer(destination);
            Message message = consumer.receive();
           
            if (message instanceof TextMessage){
                TextMessage textmessage = (TextMessage)message;
                System.out.println("Message is : "+ textmessage.getText());
            }
           
        } catch (JMSException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

App.java 

update the main class.

public class App
{
    public static void main( String[] args )
    {
        System.out.println( "Hello World!" );
       
        Sender sender = new Sender();
        sender.sendMessage();
       
        System.out.println( "Hello Receiver!" );
       
        Receiver receiver = new Receiver();
        receiver.receiveMessage();
    }
}

Execution 2

  
in the queues tab in the admin view of ActiveMQ page, will allow us to show what is happening.

Enqueue count - number of messages added to the queue
Dequeue count - number of messages removed from the queue

 

Comments

Popular posts from this blog

Oracle Database 12c installation on Ubuntu 16.04

This article describes how to install Oracle 12c 64bit database on Ubuntu 16.04 64bit. Download software  Download the Oracle software from OTN or MOS or get a downloaded zip file. OTN: Oracle Database 12c Release 1 (12.1.0.2) Software (64-bit). edelivery: Oracle Database 12c Release 1 (12.1.0.2) Software (64-bit)   Unpacking  You should have following two files downloaded now. linuxamd64_12102_database_1of2.zip linuxamd64_12102_database_2of2.zip Unzip and copy them to \tmp\databases NOTE: you might have to merge two unzipped folders to create a single folder. Create new groups and users Open a terminal and execute following commands. you might need root permission. groupadd -g 502 oinstall groupadd -g 503 dba groupadd -g 504 oper groupadd -g 505 asmadmin Now create the oracle user useradd -u 502 -g oinstall -G dba,asmadmin,oper -s /bin/bash -m oracle You will prompt to set to password. set a momorable password and write it down. (mine is orac

DBCA : No Protocol specified

when trying to execute dbca from linux terminal got this error message. now execute the command xhost, you probably receiving No protocol specified xhost:  unable to open display ":0" issue is your user is not allowed to access the x server. You can use xhost to limit access for X server for security reasons. probably you are logged in as oracle user. switch back to default user and execute xhost again. you should see something like SI:localuser:nuwan solution is adding the oracle to access control list xhost +SI:localuser:oracle now go back to oracle user and try dbca it should be working

Java Head Dump Vs Thread Dump

JVM head dump is a snapshot of a JVM heap memory in a given time. So its simply a heap representation of JVM. That is the state of the objects. JVM thread dump is a snapshot of a JVM threads at a given time. So thats what were threads doing at any given time. This is the state of threads. This helps understanding such as locked threads, hanged threads and running threads. Head dump has more information of java class level information than a thread dump. For example Head dump is good to analyse JVM heap memory issues and OutOfMemoryError errors. JVM head dump is generated automatically when there is something like OutOfMemoryError has taken place.  Heap dump can be created manually by killing the process using kill -3 . Generating a heap dump is a intensive computing task, which will probably hang your jvm. so itsn't a methond to use offetenly. Heap can be analysed using tools such as eclipse memory analyser. Core dump is a os level memory usage of objects. It has more informaiton t